CN207782789U - A kind of gis mobile terminals receiver device - Google Patents

Abstract

The utility model discloses a kind of gis mobile terminals receiver devices, it is related to a kind of receiver field, solve the distorted signals in gis message transmitting procedures, and the technical issues of improving the selective power of information transmission receiver, including sequentially connected source of sound, tuning circuit, high-frequency amplifier, frequency mixer, intermediate frequency amplifier, detecting circuit, low-frequency amplifier, gis receivers, the frequency mixer is also associated with local oscillator, the tuning circuit is preselector circuit, the intermediate frequency amplifier uses AGC intermediate frequency amplifiers, preselector circuit is using the circuit for simply coupling selection.By increasing preselector circuit, the selectivity of receiver is improved；By using AGC modules, the interference signal of receiver is effectively reduced；Have the characteristics that at low cost, interference is small, highly practical.

Description

A kind of gis mobile terminals receiver device

Technical field

The utility model is related to a kind of receivers, and in particular to a kind of gis mobile terminals receiver device.

Background technology

Selectivity is for weighing there are when adjacent channel signal, and receiver receives useful letter in its designated channel frequency Number ability, be defined as the ratio of the decaying and decaying in adjacent channel of filter for receiver on a designated channel.It influences One key factor of information transmission quality is the selective power of receiver, and selective power refers to that receiver selects desired signal Ability, can also be inhibit adjacent channel signal ability.Transmission information signal receiver is sensitive generally for improving at present It spends and has ignored selectivity, cause adjustable extent narrow, poor selectivity.Therefore, the selectivity of transmission information signal receiver is improved It is important technical problem.

The prior art use two kinds of multiplexing systems carry out it is multi channel it is preliminary it is adjacent evade, one is time division multiplexings System, referred to as TDM systems, one is frequency division multiplexing systems, abbreviation FDM systems, and frequency division multiplexing system is using frequency point Segmentation method, occupies a channel per road information, and each channel occupies certain bandwidth, the mutual not aliasing of the roads Shi Ge signal.It is receiving End frequency division multiplexing system is separated each road information using different bandpass filters.But in actual use, due to Distorted signals, caused by subsurface information transmission noise, audio mixing occurs, the case where causing semantic understanding, happens occasionally, to find out its cause, The transient pulse generated on circuit is all artifact sources, from communication, information transmission, system so that power transmission line electromagnetic radiation The interference to useful signal can all be regarded after being all received as.The noise that receiver itself generates includes amplifier, filter, mixing The noise of device, wave detector generations at different levels.Therefore, evade the distorted signals in gis information of mobile terminal transmission processes, be to be badly in need of solution Certainly the technical issues of.

Utility model content

Technical problem to be solved in the utility model is the distorted signals in gis information of mobile terminal transmission processes, with And the selective power of information transmission receiver is improved, and it is an object of the present invention to provide a kind of gis mobile terminals receiver device, solves above-mentioned Problem.

The utility model is achieved through the following technical solutions：

A kind of gis mobile terminals receiver device, including sequentially connected source of sound, tuning circuit, high-frequency amplifier, mixing Device, intermediate frequency amplifier, detecting circuit, low-frequency amplifier, gis receivers, the frequency mixer is also associated with local oscillator, described Tuning circuit is preselector circuit, and the intermediate frequency amplifier uses AGC intermediate frequency amplifiers.The tuning of receiver and passband are to choosing Selecting property plays a decisive role.Frequency characteristic receiver frequency characteristic is exactly the passband of receiver.Currently, preselector be mainly used for it is short Wave, receiving front-end of the short wave preselector as short-wave receiver, major function are to receive extremely faint short-wave signal, and incite somebody to action Signal does appropriate amplification, converts thereof into intermediate-freuqncy signal.It detects the receiving spirit that the ability of small signal directly determines receiver Sensitivity, the good linearity can reduce intermodulation distortion and crosstalk in system and channel etc..Preselector is cut by electronics Switch is changed, input frequency band is divided into several sub-bands, these sub-bands or quilt band band-pass filter limit or directly make It is used for tracking filter.Therefore, increase preselector, receiver can be reduced and receive the total load of signal and receiver can be improved Technical parameter, for receiver width accurately adapt to play a key effect.Linear distortion refers to having on amplitude or phase Change but not increase the distortion of new frequency.And the distortion when there is new frequency component to be excited is non-linear distortion.It is non-thread Property distortion be only " distortion " that people usually say.Receiver High frequency amplification and the amplitude-versus-frequency curve edge of intermediate frequency amplifier section are got over Suddenly, i.e., more preferable to the rejection ability of interference closer to rectangle.Automatic growth control AGC is instigate amplifying circuit Gain Automatic The autocontrol method that ground is adjusted with signal strength.Realize the circuit abbreviation AGC rings of this function.AGC rings are close loop electronics Circuit is a degeneration factor, it is segmented into gain controlled amplifying circuit and control voltage forming circuit two parts.Gain Controlled amplifier circuit is located at positive amplification access, and gain changes with control voltage.Control the basic portion of voltage forming circuit Part is AGC wave detectors and low pass smoothing filter, also includes the components such as gate circuit and dc amplifier sometimes.Amplifying circuit it is defeated Go out signal after detection and filtered device filter out low frequency modulations component and noise, generates to control the electricity of gain controlled amplifier Press uc.When input signal ui increases, uc also increases therewith.Uc increases make the gain of amplifying circuit decline, to make output believe Number variable quantity significantly less than the variable quantity of input signal, achieve the purpose that automatic growth control.The primary line of intermediate-frequency transformer Circle and the shunt-resonant circuits capacitance composition LC, since shunt-resonant circuit is very big to the signal impedance of resonant frequency, to disresonance The signal impedance of frequency is smaller.So intermediate-freuqncy signal generates prodigious pressure drop, and coupling on the primary coil of intermediate-frequency transformer Next stage amplification is closed, to disresonance frequence signal drops very little, is almost short-circuited, to complete frequency-selecting effect, is also improved The selectivity of receiver.

Further, the preselector circuit, including coupled capacitor Cw, the first capacitance C1, the first inductance L1, the second capacitance C2, the second inductance L2, third capacitance C3, the 4th capacitance C4, the 5th capacitance C5, the 6th capacitance C6, third inductance L3, the 4th inductance L4, the 7th capacitance C7, wherein：The one end the coupled capacitor Cw connects input terminal, and the other end is grounded after connecting with the first capacitance C1； The first capacitance C1 is in parallel with the first inductance L1；The second capacitance C2 and the second inductance L2 form series circuit, and described First capacitance C1 is in parallel；The third capacitance C3 and the 4th capacitance C4 form series circuit, in parallel with the second inductance L2；Institute The 5th capacitance C5 and the 6th capacitance C6 composition series circuits are stated, it is in parallel with the 4th capacitance C4；The 6th capacitance C6 and Three inductance L3 are in parallel；The third inductance L3 and the 4th inductance L4 is of coupled connections；The one end the 4th inductance L4 connects power supply, separately One end connects output end after connecting with the 7th capacitance L7.

Further, intermediate frequency amplifier uses single-stage intermediate frequency amplifier.The carrier frequency of this amplifier input is equal to the electricity of intermediate frequency Press signal, using simple, have the characteristics that error is small.

Further, the local oscillator uses tandem type crystal oscillating circuit.This circuit load capacitance is smaller, belongs to low negative Capacitive crystal oscillator is carried, frequency of oscillation can be accurately transferred to standard value by finely tuning load capacitance.

The utility model compared with prior art, has the following advantages and advantages：

1, a kind of gis mobile terminals receiver device of the utility model improves receiver by increasing preselector circuit Selectivity；

2, a kind of gis mobile terminals receiver device of the utility model effectively reduces receiver by using AGC modules Interference signal；

3, a kind of gis mobile terminals receiver device of the utility model has spy at low cost, that interference is small, highly practical Point.

Description of the drawings

Attached drawing described herein is used for providing further understanding the utility model embodiment, constitutes the one of the application Part does not constitute the restriction to the utility model embodiment.In the accompanying drawings：

FIG. 1 is a schematic structural view of the utility model；

Fig. 2 is a kind of preselector circuit diagram of embodiment of the utility model；

Fig. 3 is the functions of modules figure that a kind of AGC of embodiment of the utility model is controlled.

Label and corresponding component title in attached drawing：

Cw- coupled capacitors, the first capacitances of C1-, the second capacitances of C2-, C3- third capacitances, the 4th capacitances of C4-, the 5th electricity of C5- Hold, the 6th capacitances of C6-, the 7th capacitances of C7-, the first inductance of L1-, the second inductance of L2-, L3- third inductance, the 4th inductance of L4-.

Specific implementation mode

To make the purpose of this utility model, technical solution and advantage be more clearly understood, with reference to embodiment and attached drawing, The utility model is described in further detail, and the exemplary embodiment and its explanation of the utility model are only used for explaining this Utility model is not intended to limit the scope of the present invention.

Embodiment

As shown in Figs. 1-3, a kind of gis mobile terminals receiver device of the utility model, including sequentially connected source of sound, tune Humorous circuit, high-frequency amplifier, frequency mixer, intermediate frequency amplifier, detecting circuit, low-frequency amplifier, gis receivers, the frequency mixer It is also associated with local oscillator, the tuning circuit is preselector circuit, and the intermediate frequency amplifier uses AGC intermediate frequency amplifiers. The preselector circuit, including coupled capacitor Cw, the first capacitance C1, the first inductance L1, the second capacitance C2, the second inductance L2, Three capacitance C3, the 4th capacitance C4, the 5th capacitance C5, the 6th capacitance C6, third inductance L3, the 4th inductance L4, the 7th capacitance C7, In：The one end the coupled capacitor Cw connects input terminal, and the other end is grounded after connecting with the first capacitance C1；The first capacitance C1 with First inductance L1 is in parallel；The second capacitance C2 and the second inductance L2 form series circuit, in parallel with the first capacitance C1；Institute Third capacitance C3 and the 4th capacitance C4 composition series circuits are stated, it is in parallel with the second inductance L2；The 5th capacitance C5 and Six capacitance C6 form series circuit, in parallel with the 4th capacitance C4；The 6th capacitance C6 is in parallel with third inductance L3；It is described Third inductance L3 is of coupled connections with the 4th inductance L4；The one end the 4th inductance L4 connects power supply, the other end and the 7th capacitance L7 Output end is connected after series connection.As shown in Fig. 2, the circuit was inputted avoids direct current signal interference through overcoupling, then shaken by LC The further selection of circuit is swung, the FREQUENCY CONTROL for making input signal in a certain range, is transmitted to down using inductive coupling One link can be such that receiving terminal obtains within the scope of fixed frequency by the way that the parameter of capacitance and inductance is arranged by the circuit Signal effectively improves the selectivity of receiver.In this example, the frequency range of medium-wave band is 535-1605kHz, the voice of propagation Signal, frequency range 200-3500Hz, frequency bandwidth are defined as 9kHz.

In use, as shown in Figure 1, source of sound generate sound wave conversion electric signal, be transmitted to tuning circuit carry out preliminary screening, There can be higher requirement to selective using when receiver, therefore the preselector of tuning circuit can carry out more the signal of input Add accurate selection, reduce interference and improves selectivity；The signal of the suitable frequency of tuning circuit output is transmitted to High frequency amplification Device is amplified signal, and in the modulation by frequency mixer and local oscillator, output carries the carrier signal of acoustic signals, then Amplify carrier signal by intermediate frequency amplifier, filtering is interfered and improves selectivity, exports effective signal, then be transmitted to low frequency and put Big device further achievees the purpose that amplify, and is transmitted to gis receivers and realizes the output that signal is propagated.Intermediate frequency amplifier uses single-stage Intermediate frequency amplifier.The carrier frequency of this amplifier input is equal to the voltage signal of intermediate frequency, using simple, has the characteristics that error is small. The intermediate frequency amplifier works under linear condition.Intermediate frequency amplifier works under linear condition causes amplifier itself by reduction Distortion.The local oscillator uses tandem type crystal oscillating circuit.This circuit load capacitance is smaller, and it is capacitive to belong to low-load Frequency of oscillation can be accurately transferred to standard value by crystal oscillator by finely tuning load capacitance.

The intermediate frequency amplifier is controlled by the AGC of detecting circuit.As shown in figure 3, IF input signals through isolation capacitance, After matching network amplification, other clutters, then matched amplification are filtered out by bandpass filter, then controlled by three-level AGC voltages Amplification most exports DC isolation through final stage Amplification and insulation afterwards, makes up to the intermediate frequency output of 60dB gains.In view of noise and line The interference of wave, AGC control voltages have added level-one LC filter networks, have had isolation capacitance that direct current is isolated between at different levels, and three Grade AGC voltage amplifications are buffered by PIN microwave diode shapings, and+12V power supplys are added in module, at different levels to have filter capacitor pair Power supply is purified, and three-level AGC amplifications have trimmer to eliminate signal oscillating and adjustment linear gain, effectively subtract The interference that few signal is subject to.

Above-described specific implementation mode, to the purpose of this utility model, technical solution and advantageous effect carried out into One step is described in detail, it should be understood that the foregoing is merely specific embodiment of the present utility model, is not used to limit Determine the scope of protection of the utility model, within the spirit and principle of the utility model, any modification for being made equally is replaced It changes, improve, should be included within the scope of protection of this utility model.

Claims (3)

1. a kind of gis mobile terminals receiver device, including sequentially connected source of sound, tuning circuit, high-frequency amplifier, mixing Device, intermediate frequency amplifier, detecting circuit, low-frequency amplifier, gis receivers, the frequency mixer are also associated with local oscillator, special Sign is that the tuning circuit is preselector circuit, and the intermediate frequency amplifier uses AGC intermediate frequency amplifiers；The preselector electricity Road, including coupled capacitor Cw, the first capacitance C1, the first inductance L1, the second capacitance C2, the second inductance L2, third capacitance C3, the 4th Capacitance C4, the 5th capacitance C5, the 6th capacitance C6, third inductance L3, the 4th inductance L4, the 7th capacitance C7, wherein：

The one end the coupled capacitor Cw connects input terminal, and the other end is grounded after connecting with the first capacitance C1；

The first capacitance C1 is in parallel with the first inductance L1；

The second capacitance C2 and the second inductance L2 form series circuit, in parallel with the first capacitance C1；

The third capacitance C3 and the 4th capacitance C4 form series circuit, in parallel with the second inductance L2；

The 5th capacitance C5 and the 6th capacitance C6 form series circuit, in parallel with the 4th capacitance C4；

The 6th capacitance C6 is in parallel with third inductance L3；

The third inductance L3 and the 4th inductance L4 is of coupled connections；

The one end the 4th inductance L4 connects power supply, and the other end connects output end after connecting with the 7th capacitance L7.

2. a kind of gis mobile terminals receiver device according to claim 1, which is characterized in that the intermediate frequency amplifier Using single-stage intermediate frequency amplifier.

3. a kind of gis mobile terminals receiver device according to claim 1, which is characterized in that the local oscillator Using tandem type crystal oscillating circuit.